Quartzite

Powerful

Quartzite is based on the Quartz Scheduler, one of the most powerful and feature rich open source scheduling tools.
Support for sophisticated schedules, multiple calendars, Cron expressions, clustering, plugins and more.

Expressive DSL

Quartzite provides an expressive Clojure DSL for defining jobs, schedules, triggers and tying them together

Persistent Storage

Quartz supports pluggable persistence engines that preserve scheduler state between application restarts and crashes.
JDBC adapters are provided out of the box, several others (e.g. MongoDB Quartz store) are available as 3rd party libraries.

Dynamic

Unlike periodically running file-based tools, Quartzite lets you manage operations and schedules via API, query the scheduler and visualize scheduler state
on the Web or in a mobile application easily.

Battle Tested

Quartz Scheduler is a very battle tested project used actively by many commercial and open source projects, large and small.
Quartzite is a very thin layer on top of that and benefits directly from that maturity.